A downlight (also called a recessed light or canister light or can light) is a light fixture that is installed in a ceiling, such that the light source is recessed above the plane of the ceiling. Various types of conventional fixtures utilize an incandescent Parabolic Aluminized Reflector (PAR) lamp or a compact fluorescent lamp as a light source. The light output may be concentrated in a narrow beam as a spotlight, or cast in a broader beam as a floodlight.
A conventional downlight includes a housing and/or light module (e.g., containing a lamp holder) that is generally recessed in a ceiling, and a trim structure including a thin lining around the edge of the light and arranged below the housing, wherein at least a portion of the trim structure is visible when a user looks upward into the fixture. At least a portion of a trim structure may have a truncated conical shape. In a typical downlight installation, the housing (or light module) is installed first, and the trim structure is installed thereafter. Trim structures may be reflective in character (e.g., polished metal), or may have colored surface finishes such as white or black.
Solid state (e.g., LED) downlights typically utilize lenses arranged between solid state emitters and trim structures. Current technology relies on externally accessible features and attachment processes such as screws, heat staking, adhesives, or snaps for attaching a lens and/or a trim structure to a housing and/or light module. To ensure that the trim is removable from the underside of an installed downlight, a non-illuminated area around the lens may be visible (thereby compromising aesthetic appearance of the fixture), or a portion of a trim attachment structure may block or obscure a portion of the lens in the direction of intended illumination (thereby compromising lighting performance). When complex lens structures are implemented in combination with diffuser films for LED color mixing in solid state downlights, vertically arranged structural elements can become problematic by “piping” light from around the diffuser film and into the illuminated space, showing an undesirable color separation to the user. It would be desirable to provide a solid state downlight trim attachment structure permitting the illuminated lens area to flow seamlessly to a (e.g., reflective) trim structure without visible mechanical attachment elements, without blocking light transmitted through the lens in the direction of intended illumination, while permitting the trim structure to be removably installed (preferably using little effort and without tools) from below the downlight. It would also be desirable to reduce undesirable light piping in solid state downlights. It would further be desirable to utilize conventional, low-cost manufacturing techniques for fabrication of lenses and trim structures to reduce fabrication difficulties and reduce production costs.
In consequence, the art continues to seek improved lens and trim structures for solid state downlights, as well as improved downlights including such structures and methods for fabricating same.